Shaft seals are known that are mountable on stationary or rotatable shafts to prevent or substantially prevent or controllably allow the flow of a fluid from one side of the seal to the other. Such seals may include radially inner and radially outer seal members that rotate relative to each other with little or no space therebetween to provide the sealing function. The outer surface of the inner seal member and the inner surface of the outer seal member may be substantially cylindrical or, alternately, may have complementary non-cylindrical shapes. As an example, the inner seal member may have one or more annular ridges that is/are received within corresponding grooves on the outer member. Such seals may be referred to as “labyrinth seals” and provide a labyrinthine pathway to affect the rate at which a fluid can move from one side of the seal to the other.
Shaft seals may be mounted at an end of a shaft or in the middle of a shaft with or without other elements being present between the seal and an end of the shaft. When the inner and outer seal members are each formed as unitary rings, the seal elements must be mounted on the shaft axially by passing them over one end of the shaft and moving them to a desired location. When it becomes necessary to remove such seals for inspection, repair or replacement, however, all elements between the seal member and the end of the shaft must be removed to allow the axial removal of the seal member. Certain types of labyrinth seals may also be difficult to assemble or disassemble without significantly stretching the outer seal member to allow it to fit over projections on the inner seal member.
Some of these problems may be addressed by split seals. In a split seal, the inner ring member, the outer ring member, or both are formed from generally cylindrical members that are split in half. Thus, rather than sliding these seals axially over the end of a shaft during installation, they can be placed radially on either side of a shaft at a desired location and moved toward one another and joined. This joining may be accomplished, for example, by screws or other fasteners screwed into the seal member from a radially inner or radially outer surface, the screws extending either radially or along a chord of the circular cross section of the seal. However, in some installations, it may be difficult to access the fasteners that hold the two halves of the seal member together. It would therefore be desirable to provide a split shaft seal in which multiple components of the seal are held together with easily accessible fasteners.